The installation proceeded with no errors, and the 5 Windows services start
up OK. But I found that I could not connect to the database web-based admin
interface.

An additional symptom was that I can't change my domain password, nor
create Windows local user accounts. In both cases, the error was that the password
does not meet the requirements on characters and length. HP has tighter
guidelines than the default for passwords but why installation of OracleXE broke a part of WindowsXP, I don't understand. After uninstalling OracleXE, I could change my password and create local user accounts as usual.

There are lots of articles about not being about to contact the database home
page but only a few were related to the situation I had:
this one was most useful
(that link is into the OracleXE forum which is not
publicly readable - you have to register first).

A way to see if your installation has been affected is to see if there is a
file server\dbs\SPFILEXE.ORA. If not, the installation is
probably broken.

Logging in as the local administrator account, uninstalling, reinstalling got
an installation where I could get to the database home page and administer the
database. I guess any local user account in group Administarors would work.

But sqlplus.exe still didn't work. (The error is
"ORA-12638: Credential retrieval failed").
Following that thread again, I changed SQLNET.ORA to
SQLNET.AUTHENTICATION_SERVICES = (none) and could
connect to the database from the SQL command prompt.

Afterwards ...

Installing on Windows XP/Home worked fine but that is not a domained machine.

And after all that, the SDBSPARQL test suite
runs perfectly with OracleXE.

22 June 2007

New version of Joseki released, primarily to
package together all the updated jars files for Jena and ARQ that Joseki uses. At the same time, other jars have been upgraded so there are jar naming changes.

10 June 2007

This describes an extension to SPARQL for path variables. A path is a regular expression of properties but in addition the paper describes the need for reverse properties and constraints on paths (like length).

This is a proposal for reduced RDFS with just rdfs:domain, rdfs:range, rdfs:subClassOf, rdfs:subPropertyOf and rdf:type.

This results in (on page 8) a small set of rules that have to be applied to the data but there is no core vocabulary. The rules can be applied to a streaming data stream, if the RDFS schema is known, because each rule only refers to at most one data triple.

There are no containers, which may be inconvenient, but that might more usefully be covered by not using typing, but having a different property just to match these syntactic constructs. That removes the container vocabulary from interacting with the application vocabulary.

A colleague here, Nipun Bhatia, has been working on streaming checking and rule application based on extending Eyeball. Nipun even adds cardinality validation by preprocessing the data to get
the triples in subject order. Unix sort(1) is quite capable of sorting very large N-triples files in sensible amounts of time.

((Non) interest declaration: Markus is now spending a few months working with us in Bristol - this work was done before that.)

The core of this paper is an example where statistical techniques beats logic. There is a strong message to us all here - don't think logic and perfect organization is
necessarily the best solution to actual problems.

As part of this work, but not the main argument of the paper, they created iSPARQL (i=inprecise) which is an embedding of access to similarity metrics inside standard SPARQL without syntax changes. They use property functions (they are using ARQ but the principle is quite general) to access the similarity engine.

The idea of embedding some index or other functionality that can provide bindings of variables for some expression seems like a general extension technique for SPARQL. LARQ provides free-texting matching, using
Lucene to do matching, and can include all the Lucene loose matching